// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_
#define UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_

#include <vector>

#include "base/macros.h"
#include "base/strings/string16.h"
#include "ui/base/ui_base_export.h"

namespace ui {

class Accelerator;

// A model representing the rows of buttons that should be inserted in a button
// containing menu item.
class UI_BASE_EXPORT ButtonMenuItemModel {
public:
    // Types of buttons.
    enum ButtonType {
        TYPE_SPACE,
        TYPE_BUTTON,
        TYPE_BUTTON_LABEL
    };

    class UI_BASE_EXPORT Delegate {
    public:
        // Some command ids have labels that change over time.
        virtual bool IsItemForCommandIdDynamic(int command_id) const;
        virtual base::string16 GetLabelForCommandId(int command_id) const;

        // Performs the action associated with the specified command id.
        virtual void ExecuteCommand(int command_id, int event_flags) = 0;
        virtual bool IsCommandIdEnabled(int command_id) const;
        virtual bool DoesCommandIdDismissMenu(int command_id) const;

        // Gets the accelerator for the specified command id. Returns true if the
        // command id has a valid accelerator, false otherwise.
        virtual bool GetAcceleratorForCommandId(int command_id,
            ui::Accelerator* accelerator)
            = 0;

    protected:
        virtual ~Delegate() { }
    };

    ButtonMenuItemModel(int string_id, ButtonMenuItemModel::Delegate* delegate);
    ~ButtonMenuItemModel();

    // Adds a button that will emit |command_id|. All buttons created through
    // this method will have the same size, based on the largest button.
    void AddGroupItemWithStringId(int command_id, int string_id);

    // Adds a button that has an icon instead of a label.
    void AddItemWithImage(int command_id, int icon_idr);

    // Adds a non-clickable button with a desensitized label that doesn't do
    // anything. Usually combined with IsItemForCommandIdDynamic() to add
    // information.
    void AddButtonLabel(int command_id, int string_id);

    // Adds a small horizontal space.
    void AddSpace();

    // Returns the number of items for iteration.
    int GetItemCount() const;

    // Returns what kind of item is at |index|.
    ButtonType GetTypeAt(int index) const;

    // Changes a position into a command ID.
    int GetCommandIdAt(int index) const;

    // Whether the label for item |index| changes.
    bool IsItemDynamicAt(int index) const;

    // Gets the accelerator information for the specified index, returning true if
    // there is a shortcut accelerator for the item, false otherwise.
    bool GetAcceleratorAt(int index, ui::Accelerator* accelerator) const;

    // Returns the current label value for the button at |index|.
    base::string16 GetLabelAt(int index) const;

    // If the button at |index| should have an icon instead, returns true and
    // sets the IDR |icon|.
    bool GetIconAt(int index, int* icon) const;

    // If the button at |index| should have its size equalized along with all
    // other items that have their PartOfGroup bit set.
    bool PartOfGroup(int index) const;

    // Called when the item at the specified index has been activated.
    void ActivatedAt(int index);

    // Returns the enabled state of the button at |index|.
    bool IsEnabledAt(int index) const;

    // Returns whether clicking on the button at |index| dismisses the menu.
    bool DismissesMenuAt(int index) const;

    // Returns the enabled state of the command specified by |command_id|.
    bool IsCommandIdEnabled(int command_id) const;

    // Returns whether clicking on |command_id| dismisses the menu.
    bool DoesCommandIdDismissMenu(int command_id) const;

    const base::string16& label() const { return item_label_; }

private:
    // The non-clickable label to the left of the buttons.
    base::string16 item_label_;

    struct Item;
    std::vector<Item> items_;

    Delegate* delegate_;

    DISALLOW_COPY_AND_ASSIGN(ButtonMenuItemModel);
};

} // namespace ui

#endif // UI_BASE_MODELS_BUTTON_MENU_ITEM_MODEL_H_
